Telegraph transmitter



ENTOR.

May 6, 1941- L. M. PoTTs 2,241,271

TELEGRAPH TRANSMITTER Original Filed Se'pt. 26, 1 936 3 Sheets-Sheet 1 l li .mmhmimhu I LOUIS May 6, 1941- L. M. POT-rs TELEGRAPH TRANSMITTER s sheets-'smet 2 Original Filed Sept. 26, 1936 FIG.3

q sLow To OPERATE INVENTOR. LOUIS M. POTTS INVENTOR. LOUIS M. POTTS A ORNEY.

s sheets-'sheet s May 6, 1941. M. PoTTs TELEGRAPH TRANSMITTER Original Filed Sept. 26, 1936 Patented May 6, 1.941l

TELEGRAPH TRANSMITTER Louis M. Potts, Evanston, Ill., asslgnor to Teletype Corporation, Chicago, Ill., a corporation of Delaware Application September 2G, 1936, Serial No. 102,771 Renewed October 18, 1939 21 claims. (o1. 17e-17) The present invention relates to telegraph signaling apparatus and more particularly to transmitters for issuing telegraph signals identified with printing telegraph systems.

Among methods of telegraph communication, two systems of telegraph transmission in general usage are known as permutation or Baudot code and step-by-step code. The former system vof transmission utilizes an equal length time interval as a signal unit during which a definite number of sub-intervals are identified with predetermined electrical signal conditionsV in accordance with a permuted code consisting of five or six of said sub-intervals or signal elements. Both systems of transmission are used extensively and independently of each other but for some purposes of signal communication it is deemed desirable to be able to employ permutation code signalsv for trunk line or general dissemination and step-by-step signals for local communication and printing operation.

Accordingly, an object of the present invention 'is to provide simple, inexpensive, and reliable apparatus for converting permutation code signals into so-called step-by-step signals.

Another object of the lpresent invention is the provision of apparatus for converting permutation code signals manifest by transverse perforatons inthe control form into groups of step-bystep line variations.v

. 1n contemplating' the foregoing objects there are taught in the following disclosure, two fundamental embodiments of construction, one utilizing electromagnets in the translation from one code to the other,while a second embodiment utilizes an al1-mechanical apparatus for accomplishing the same purpose. A pin barrel selector mechanism is provided with a coded series of discs, the -periphery of which is notched. A plurality of selectable pins distributed about the discs are individually selectable to respond by a shifting motion. With each change of code signals, a previously conditioned selector pin is cammed out as its successor is selectively actuated. A shaft concentric of the selector mechanism carries a seeker arm which is frictionally; driven and which is arrested upon its encountering a selected pin. The restoration of each pin to its normal or unactuated position releases the seeker `arm which thereupon rotates until it encounters a subsequently selected pin, describing a predetermined angle of rotation and permitting the concentric shaft to rotate accordingly through a v measured angular distance. A line interrupter also carried by the shaft causes to be generated a succession of current variations which, by their number, indicate the angular rotation of the transmitter shaft. A step-by-step printing mechanism designed in accordance with the signal transmitter shaft consummates a printing shaft rotation under the control of the step-bystep signals thus communicated.

For a more comprehensive understanding of the present invention, attention is directed to the 4detailed specification following hereinafter and to the illustrations in the accompanying drawings, in which Fig'. 1 is an end elevation of a translator mechanism having portions broken away and embodying the principles of the present invention;

Fig. 2 is a longitudinal sectional view of the apparatus disclosed in Fig. 1 and is taken approximately on line 22 thereof;

Fig. 3 is a circuit diagram illustrating the electrical connections of the apparatus featured in Figs. l and 2;

Fig. 4 is an end elevation with parts broken away of a modified apparatus featuring an allmechanical translator unit; and

Fig. 5 is a longitudinal sectional view taken approximately on line 5-5 of Fig. 4.

Referring now particularly to Figs. 1, 2, and 3,

the reference character I I indicates a supporting wall or xture upon which there is mounted a stationary sleeve I2 having spacer flanges I3, one of which abuts the supporting wall I I and the other an endmost plate I4. Concentrically of the stationary sleeve I2 there passes a transmitter shaft I5 journalled in the bearings I6 and tending to be driven by a pinion I'I which is supported between the felt slip Washers IB--IB of a clutch assembly I9. The driven pinion I'I is connected in driving relationship with a worm 2l which in turn is secured to a power shaft 22 which revolves at the reception rate of a step-by-step printer or any other step-by-step receiving mechanism.

l The rotation of shaft I5 is permitted until a stop arm 23, carried at its right end, Fig. 2, collides with the extremity of a selected one of a plurality of selector pins 24 circumferentially arranged about the sleeve I2 and supported at one end within the already mentioned end plate I4 which is suitably notched to receive said pins 24, at an intermediate point Within a plate 25 which is similarly notched but whose notches 26 are cut deeper than are those of plate I4, and at their other ends by an end plate 21 Whose notches 28 are deep cut and more nearly like those of plate 25. The pins 24 are shaped to afford a pair of ripples as at 29 about which there are held in position a pair of garter springs 3I. A tie-in spring 32 resembling the garter springs SI fits about the outwardly turned end portions 33 of pins 24, as indicated in Fig. 2, maintaining them against longitudinal displacement as the garter springs 3I urge the several pins 24 inwardly.

` Near their right ends selector pins 24 are provided with friction reducing rollers 34 which align with and engage the periphery of associated selecting discs 35, see also Fig. 1. The discs 35 are freely rotatable upon sleeve I2 and are designed in accordance with a plan so that each disc "is peculiarly notched to afford various `V-shaped projections and complementary intervening notches. The distribution of 'the projections and the notches of discs"35issuch`that for each angular disposition of the several of them there may be aiorded a transverse'alignnient of notches beneath the rollers 34 of one of the selector pins 24, permitting said selector pin 24 to drop into a position such as that'indicated by the posterior pin seen inthe upper portion of Fig. 2. When in this position; the extremity of a selector pin 24 lies in the path of the end of stop arm 23.

Selecting discs 35 are each shifted through but a slight angular distance, and'for regulating this movement each disc is controlled by a rock shaft 36 which is `iournalled at 31 in the endV plate 2'I and at 38 in the end plate I4. Each rock'shaft 36 passes through the openings 33 of the several of said selecting discs 35 but aligning opposite one of said discs Within its opening 39 an arm 4I secured to shaft 36 is articulated by a disc and slot connection, as indicated 42 in Fig. 1. An arm 43 secured to each rockV shaft-36 serves as an armature under mutual control of a pair of magnets 44 and 45, so that upon the energization of a magnet 44, an armature 43 and its associated rock shaft 36 is rocked counterclockwise (Fig. 1), causing through arm 4I a particular one of the selecting discs 35 to be similarly shifted, while upon the energization of the other of each pair of magnets 45, selecting disc 35 is rotated clockwise. Each selecting disc 35 is in this manner under the control of a pair of magnets 44-45,

see also Fig. 3. The energizing circuits for the magnets 44 are traceable in Fig. 3 from ground through battery 46, conductor 41, the winding of each of the magnets 44, thence over individual conductors 48-I to 46-5 to the lower Contact f points 49 of the levers 54 of the tape sensing Vunit generally indicated 5I, the contactors of any levers 54 in its counterclockwise position,com mon conductor S I, contact pair 68-75, to-ground.

The circuits of magnets are traceable in the same manner from ground and battery atr46,

through the conductor 41, winding of magnets 45, thence over individual conductors 52-I to 52--5 to the upper contact points 53 of the feeler levers 54 of the tape sensing unit 5I, the con= tactors of any lever 54 in its clockwise position, common conductor 9i, contact pair 68-75, to ground. When a feeler lever 54 is presented in its counterclockwise position, which is its'response pursuant to encountering a perforation in a tape perforated in accordance with a permutation code, its grounded contacter is disposed to communicate with the so-called marking-contact 49, causing to be energized a magnet 44, but when'a feeler lever encounters an unperforated position in the tape, it is caused to'be disposed in its clockwise position whereat its contacter engages its so-called spacing contact 53, causing to be energized, instead, a magnet45.

As has already been said, the energiaation of the magnet 45 results in theshifting of a par- 'ticular selecting discv 35 clockwise or into its spacingV position." While'the; enrgi'zation of the magnet 44V causes its associated selecting disc 35 to be shifted to its counterclockwise or marking position. As each set of perforations (five in the instant case) is sensed by the feeler levers 54, the ve selecting discs 35 are correspondingly positioned, causing to be selected a particular one of the selector pins 24 and concurrently camming out the preceding selected one of the pins 24. This causes stop arm 23 and shaft I5 to be released from one angular position and to rotate until arm 23 encounters another pin 24, describ ing as 'it does so,` a measured or predetermined angle of rbtation.

Stop arm 23 carries a pair of pivot pins 55 and 56 Yupon the former of which there is supported a lever 5'I, the outer end of which is formed with a skid portion 58. As stop arm 23 is rotated in passing from one selected position to another, an

oncoming selector pin 24 is lencountered by theA skid lever 5'I which thereupon rocks clockwise as viewed in Fig. 2, about its pivot 55. This motion on the part of lever 5l communicates a counterclockwise movement to a lever 59 which is pivoted onf pin 56. The innermost end of lever 59 .terminates asv at 6I with a ball which is disposed in line-with the axis of transmitter shaft I5 and .which at all times engages'one blade 62 of a pair vpair 'I3 (which is normally closed), line 14, contact pair R51- 69, and part of the winding of relay 6,6 to ground. VRelay 66 is thus maintained energized after the skid 58Y has passed over a selected pin 24 and has'returned to its normal position, as viewed in Fig. 1. As a result ofthe movement of contactor 68 from its back contact I5 to its front contact 1I, there is prepared a circuit which is traceable from grounded battery at '16,

vthroughthe winding of a slow-to-operate relay I'I,' conductor 18, and contact pair 68-'II to ground. Since relay .TI is slow to operate, there lapses an interval before the completion of a circuit which is traceable from grounded battery at I ll, through the Winding of a solenoid 8l which returns the feeler leversl 54, conductor 82, and contact pair 83 to ground. The closure of contact pair 8 3 is the result of the operation ofV slow relay 'Il and results in the actuation of solenoid 8l, which moves its plunger 84 letwardly, Fig. 3, causing a counterclockwise rotation of the return bail 85 which rocks the several feeler levers V54Wclockwise and which alsoA closes a circuit traceable Afrom grounded battery at 86, through the winding-of release-relay 8'I, conductor 88, and

.contact pair 89 whichiis closed as a result of the movement of bail 85 to ground. As a result of the delay introduced by the operation of relay .l'I there is eiected a prolonged signal or marking condition over the line 93.

This signal operates at the remote station to energize a slow-to- `operate relay, Which results in producing a print operation in a manner well known in the present art. The construction of` sensing unit 5I and the manner in which solenoid 8 I operates to Withdraw the feeler levers cyclically'is not fundamental; to the'present invention'but for a comprehensive understanding of4 such a'record reader arrangement, reference may be had to a publication entitled Tape Duplex System Bulletin No.

101 published by the Morkrum Company and copyrighted in 1918, wherein Fig. 14 illustrates an arrangement of feeler levers which may be employed in a system such as is here featured Y in Fig. 3. A

As a result of the energization of release relay 81, the contact pair 13 is opened, breaking the aforedescribed locking circuit for relay 66 and permitting the release of armatures 61 and 68 of relay 66. Armature 68, in closing its back contact 15, reestablishes ground to conductor 9| which communicates as at 92 with each of the feeler levers 54 and their contactors. As a result, several circuits, 48 or 52, are simultaneously prepared, causing to be energized the magnets 44 and/or 45 in accordance with a newly presented code signal. A f

In response to the aforedescribed supervision of transmitter shaft |5, there is imparted to it angular rotation of varying degrees, depending of course in each case upon the angular distance between a previously arrested position and a succeeding one. Step-by-step line signals are issued over a line 93, Fig. 3, when an interrupter camI 94, secured to shaft and having a plurality of cam projections on its periphery, engages and actuates the reciprocating contact spring 95 between its negative supply contact 96 and its positive supply contact 91. These current pulsations impressed on line 93 may then be used in the control or energization of a conventional pallet escapement or contactors of a step-by-step printing mechanism such as the step-by-step stock ticker. In lieu of positive and negative puli sations, current and no-current signals may be employed as is well known in the .art of printing telegraphy. In accordance with well-known telegraph printing devices, the prolonged or continuous signal which follows a series of said puli sations or current variations is employed to energize a slow-to-operate relay which thereupon consummates a printing function by releasing a print hammer or by executing a type printing operation.

Modifications In Fig. 4, a tape sensing device is indicated generally |01. Here too there are employed a plurality of tape feeler levers |02 pivoted at |03, l

and reciprocated between a clockwise extreme position as illustrated in Fig. 4 and a counterclockwise position which is influenced by individual springs |04 during which the feeler pins |05 protrude through the table |06 and the con trol tape, and during which the limiting bar |91 will touch the opposite surface of the oversized aperture |08. In accordance with the position of the several feeler levers |32, their transfer projections |09 and are correspondingly placed so as to communicate a symmetrically opposit-e movement to an associated one of a plurality of transfer levers ||2 Whose articulation discs ||3 are fitted into recesses ||4 of a set of selecting discs ||5 which correspond to the selecting discs 1 35 aforedescribed. In the embodiment under discussion, the selector pins ||6 are grouped to occupy but one-half of the peripheral space surrounding the barrel assembly while the stop arm lever ||1 is of a duplex nature having a sys-` tem of levers H8 and ||9 at each end. The setting of the feeler levers is communicated to the selecting discs ||5 by the transfer levers ||2 as aforesaid when the supporting bail |2| which carries the several transfer levers ||2 is rocked to and fro by the bell crank |22 which is pivoted at |23 and whose follower roller |24 is actuated by a quadruple cam |25. The shaft |26 carries an assembly sleeve |2 1 upon which is integrally formed not only the aforementioned cam |25 but also a tape feeler and feed cam |28 and a stop disc |29. Assembly sleeve |21 is frictionally carried upon a journal bearing |3| between slip washers |32 under tension of a clutch spring |33. Motion is imparted to shaft |26 from a prime operating shaft |34 whose worm |35 drives not only the gear |36 of shaft |26 but also a gear |31 which is frictionally carried upon the distributor shaft |38. Thus while shaft |26 is rotated continuously and its driven sleeve |21 is periodically released for rotation, gear |31 is driven continuously and the entire distributor shaft |38 is released for rotation only periodically.

Driven gear |31 is supported between a pair of slip washers |39 in a clutch assembly |4|. Shaft |38 is journalled at |42|42 in frictionless bearings and carries at its remote end the aforementioned duplex lever ||1 whose arms ||8 and ||9 function in a manner quite similar to the aforedescribed levers 51 and 59. That is to say, as a particular lever system is passing through the vicinity of the selector pins ||6, a skid |43 integrally formed with the levers |8 encounters and is rocked by a selected one of the selector pins H6, the latter being conditioned by the discs ||5 in the same manner as described in the preferred embodiment. In this construction, however, the movement of the intermediate levers ||9 causes to be imparted a corresponding movement to a clutch release lever |44 which is pivoted at |45 and which is articulated as at |46, Fig. 5, to a bell crank |41 pivoted at |48, which actually stops the assembly sleeve |21 by its intervention before one of the teeth of stop disc |29. Thus, while the communication of a particular code signal to the discs |15 causes shaft |38 to be released, assembly sleeve |21 is not released until the newly selected selector pin I6 has been encountered by stop arm ||1 whereupon the apparatus is in readiness to receive a new signal for which assembly sleeve |21 is freed to execute its tape advancing, feeler withdrawal, and rearresting functions. It will be noted that the cam and disc assembly carried by sleeve |21 is designed to afford quadruple actuating elements. That is to say, the assembly need consummate but one-fourth revolution in order to actuate the tape feed lever |54 and through its bail |55 the several feeler levers |02, While the bell crank |22 is effecting the transfer operation.

In the modied apparatus featured in Figs. 4 and 5, the selecting discs I5 are coded throughout but one-hall` of their periphery as may be noted from the distribution of the selector pins ||6. This arrangement permits of certain conveniences in assembly, but in order to constitute each half revolution of distributor shaft |38 subservient to signal propagation, there is provided the aforementioned duplex lever' |1, each arm of which is effective for a half cycle of revolution, while its opposite arm is idle. As in the case of the preferred embodiment, the selector pins ||6 are retained and influenced inwardly by a garter spring |49 and a tie-in spring |5|. Also as in the preferred embodiment, an interrupter cam |52 is secured to distributor shaft |38, causing to be alternately made and broken the contact pair |53, which generates current pulsations in a signaling line.`

In this embodiment, it is to be noted that the tothe selecting discs VI |'5 by mechanical devices.

In a'fzcordance with Vthe transverse perforations Vbe shifted andV to assume positions corresponding to those of the feeler levers |02'. As a result, a particular selector pin I |6 is cammed out of selected position and another one received into selected position. This frees lever I |'|,'perrnittingl it to rotate throughout a portion of a revolution until iii-encounters the newly selected pin IIS whereat it is again arrested. As 'a skid l M3 approaches the foremost portion of a newly selected pin H6, it is rocked about its pivot, giving motion to the innermost lever H9 and causing the stop bell crank |41 to be withdrawnmomentarily from stop disc |29, which permits shaft |26 to be initiated into another quarter revolution, for bell crank lill is immediately restored t-o its normal position as skid V|43 and its train of levers glide over the selectedpin H6 f and are permitted to resume their normal position.

Meanwhile, shaft |38 has been permitted to describe a predetermined degree of rotation coru respondingr to the angular distance between its previously arrested position and its current one.

VThis angular Arotation is manifest byv a corre'- sponding number of line pulsations which 'are generated by the cam |52 andthe contact pair |53' vWhile the present invention has been explained and described in accordanceiwith specifically illustrated embodiments, it will be noted that numerous modifications may be invoked without departing from the spirit ofthe present invention, as defined by the hereinafterappended claims. L i

Ylll/'hat is claimed is:

1. A telegraph transmitter comprising a rotary member, a plurality ofy actuators for conditioning'said member, a line switch'actuable in accordance with theangular rotation of "said rotary member, a stop means associated'withsaid rotary member and controlled by said actuators for Vdetermining the angular rotation thereof, saidplurality of actuators individually conditioned to block said stop means, a set of selecting discs for conditioning said plurality of actuators, a" tape sensing mechanism for positioning said discs in accordance with the control markingsof'a tape including means for' advancing said tape intermittently, and apparatus for initiating said Ytape advancing means under the control of said rotary member.

2. A telegraph transmitter comprising a selector mechanism, a rotary membencoitrolled :in its travel by said selector mechanism, a transmitter including a line switch actuable in accordance with the rotation of said rotary member, a'controlling skid lever supervised by'said rotary member, a tape sensing mechanism, and means associated withjsaid skid lever for initiating said tape sensing mechanism response to predetermined opereteeiei'saidretarr mber.

2,241,271 condition of the perforated tape is communicated 3. In combination, a transmitter mechanism actuating'shaft andV a tape sensing mechanism actuating shaft, a pulsator carried by said transmitter actuating shaft for generating line variations to control step-by-step printing mechanism, a stop arm carried by said transmitter actuating shaft having an extremity which traverses a path, a' plurality of individually selectable elements disposed in alignment bordering said path, a set of permutation code discs for individually conditioning each 'element to be moved intosaid path of said stop member, a set of permutation code tape sensing levers, means for 'cyclically withdrawing said levers, a control tape feeding apparatus cyclically actuated by said sensing mechanism shaft, and means under the control of saidV stop arm for releasing said sensing mechanism shaft periodically.

ll. AIn `a telegraph transmitting mechanism, a record reader comprising a set of 4tape sensing elements and a tape advancing member, aset of coded selectors, means to communicate a permutation code setting from said tape sensing elements to said set of coded selectors cyclically, a plurality of selectable members individually conditioned by said selectors, an apparatus traversing the proximity of said plurality of selectable members and arrestable by a conditioned member, said apparatus including means for initiating the operation of said tape advancing member, a pair of contacts, Aan 'interruptor for intermittently opening and closing said contacts, and means under the control of said traversing apparatus for actuating said interrupter during the interim between passing from a selected one of said members to a subsequently selected member.

5. I n a telegraph transmitting system, means to generate various pluralities of signal interruptions each representing a character comprising a rotatable member, a plurality of elements each'assigned to a character and peripherally distributed about said rotatable member, means conditioned by perforations in a control form to present selectively one of said plurality of members into the path of said rotatable member, and means actuated by said rotatable member for initiating the performance of said conditioned means to respond to subsequent perforations in said form;

6; The combination set forth in claim 5 in which said means is conditioned by a plurality of form sensing members, an electromagnet for 'cyclically restoring said form sensing members to permit the advancement of the form, and a delayed response relay for energizing said electromagnet to withdraw said form sensing members after the lapse of a predetermined time interval.

l'l'. In a transmitting mechanism, a device for generating line pulsations comprising a rotatable member, a selecting apparatus for arresting said member in various angular positions, a control form sensing apparatus comprising means for ascertaining control form markings and means lfor`ffeeding a form to present subsequent markingsv to said`ascertaining means, sensing apparatus initiating means under the supervision of said rotatable member, and means for communieating a setting from said ascertaining means to said selecting apparatus for each operation of said form feeding means.

` 8. In a telegraph transmitting mechanism, a

' transmitter shaft including means for generating signal interruptions corresponding to the angular miettes esaidebeft/e tape Sensing mechanism comprising a set of tape sensers and a tape feed mechanism, a power shaft including a frictional coupling for communicating the actuating power to said tape sensing mechanism, means under the control of said tape sensing mechanism for determining the angular position of arresting said transmitter shaft, and means responsive to an arrest of said transmitter shaft for establishing the coupling between said tape sensing mechanism and said power shaft.

9. The combination set forth in claim 8l in which said transmitter shaft and said power shaft are driven from a common source of power.

10. In a selector mechanism, a plurality of circular discs in concentric alignment having peripherally thereof notch and lug selecting attributes, a plurality of selectable rods spaced and aligned around said alignment of discs, spring means for urging said rods into engagement with the periphery of said discs, a frictionally driven shaft concentric of said discs, a seeker arm carried by said shaft having Yan extreme member which traverses the proximity of said rods and is actuable by a conditioned one of them, and a mean member moved by said extreme member having a contact controlling portion disposed in alignment with the axial center of said shaft.

11. The comb-ination set forth in claim 10 in which said seeker arm is provided with duplex extreme and mean elements, and in which said plurality of selectable rods are confined to occupy substantially one-half of the periphery of said discs.

12. In a device for converting permutation code l signals into step-by-step signals, the combination including a rotatable shaft, frictional driving means for imparting rotation to said shaft, an interrupter carried by said shaft for generating line pulsations, means for controlling the angular rotation of said shaft comprising a set of disc selectors, a plurality of selectable pins peripherally distributed about said set of selectors and movable during selection into an arresting zone, a tape feed mechanism for advancing a control form to supervise the positioning of said disc selectors, a switch controlling stop member carried by said shaft and blocked by said pins when moved into said arresting zone, and means carried by said stop member for controlling said tape feed mechanism.

13. In a telegraph transmitting mechanism, means for generating alternate current conditions for signalling over a line including a rotary arm, a permutation selecting device, means under the control of said permutation selecting device for arresting said rotary arm in various angular positions, and means under the control of said arm for determining the instantV of restarting said arm into rotation.

14. A telegraph transmitter comprising a switch for generating current interruptions, a rotary member for actuating said switch, a plurality of selectable elements, and means for individually conditioning sai selectable elements to arrest said rotary member predeterminedly in its cycle of rotation, said conditioning means comprising a set of discs having sets of aligned openings, and means for setting said discs including a set of shafts one associated with each of said discs and extending through one of said sets of alignment of openings, and cam means carried by said shaft secured in transverse alignment each with its associated one of said discs.

15. In a selector mechanism, a set of parallelly arranged selector members having transversely aligned openings therethrough, and means for setting said members in accordance with the permutation components of a code comprising a device extending through each alignment of openings and associated with one of said members, and a projection carried by each of said devices for communicating a setting movement from said device to its said associated member.

16. In a code translating apparatus, a power driven instrumentality, a record reader including an intermittent feeding device driven by said power instrumentality, a selective translator including a rotary switch controller driven by said instrumentality, and a mechanical linkage under the supervision of said rotary switch controller for permitting the engagement of said power driven instrumentality and said feeding device.

17. In combination, a selector mechanism including a set of code members having various distributions of notches and lugs for establishing individual selective clearances, tape controlled means for positioning said code members, and all-mechanical means responsive to each selective placement of said members for advancing a tape through which said selector mechanism is controlled.

18. In combination, a plurality of selectively conditionable devices arranged in a circular path, a rotary seeker driven to traverse said path and responsive specially to any of said devices in selected condition, means for generating signal interruptions during the transitori,7 period of said seeker moving from one conditioned one of said devices to another, a record sensing mechanism responsive to perforaticns in a tape for selectively conditioning said devices in accordance with related perforation signals, and means under the control of each special response cf said rotary seeker for operating said record sensing mechanism.

19. The combination set forth in claim 18 in which said selectively conditionable devices are arranged in a semi-circular path and in which said rotary seeker is a duplex member having identical opposite portions each effective during one-half of a revolution.

20. In a mechanical permutation selector mechanism, a set of rotationally shiftable code elements having peripherally thereof selection clearances and obstructions, a plurality of selectable elements surrounding said discs, means for individually selecting said elements by permutative presentment of said selection clearances under individual disposition of said discs, and mechanical means for shifting said discs comprising rock shafts extending through openings in said discs and longitudinally of their axis of rotation, signal responsive means for imparting movement to said shafts, and elements individual to each cf said shafts having articulation with corresponding ones of said discs.

2l. In a telegraph transmitter, a rotatable signal controlling member, selectively conditionable means for arresting said member variously including a perforated tape sensing mechanism, and apparatus including said rotatable member and a selection responsive means for regulating the progress of tape in said sensing mechanism.

LOUIS M. POTTS. 

